Moving supplies and evacuating casualties from the edge of the front lines — the proverbial “last mile” — has becoming increasingly hazardous. In addition to fire from traditional weapons like artillery, machine guns and snipers, drones now present a threat. So, the U.S. Army would like a robot to do the work. The service is seeking an unmanned ground vehicle that can handle both casualty evacuation and resupply for tactical units. “The modern battlefield is characterized by persistent enemy